..Photoreceptor cells of vertebrate eyes are fundamentally different from those of invertebrate eyes. New work on the brain of a ragworm now suggests that ancestral bilaterians possessed both types of photoreceptor cell...

..We argue that this may be useful in eyes serving a single visual task. The findings indicate that tailoring of complex receptive fields might have been one of the original driving forces in the evolution of animal lenses...

..They also hold a lens-like structure, but its optical power is minute. Optical modeling suggests spatial resolution, but only in one plane. These unique and intriguing traits support strong peripheral filtering...

Temporal properties of the lens eyes of the box jellyfish Tripedalia cystophora

..Here we expand this knowledge by demonstrating the presence of molecularly preserved melanin in intimate association with melanosome-like microbodies isolated from an argentinoid fish eye from the early Eocene of Denmark...